What must a UK invoice legally include?

What does every UK invoice have to show?

GOV.UK lists nine items that every invoice must include, whether or not you are VAT-registered and whatever your business structure.

1. A unique identification number
2. Your company name, address and contact information
3. The company name and address of the customer you are invoicing
4. A clear description of what you are charging for
5. The date the goods or service were provided (the supply date)
6. The date of the invoice
7. The amount(s) being charged
8. The VAT amount, if applicable
9. The total amount owed

Two of these cause most of the mistakes. The supply date and the invoice date are different things: if you finished the work on 14 May and invoiced on 20 May, both dates appear. And “unique identification number” means a sequence, not a random reference; invoice 0024 should follow 0023.

What extra must sole traders and limited companies add?

Sole traders must show their own name as well as any business name they trade under, and an address where legal documents can be delivered. A limited company must use its full company name exactly as it appears on the certificate of incorporation, including “Limited” or “Ltd”. If a company chooses to put directors’ names on its invoices, it must list every director, not just one. Most companies also print their company number and registered office, which is required on business letters and websites, so it is simplest to treat the invoice the same way.

What does a VAT invoice need on top?

Once you are VAT-registered, which is compulsory above £90,000 of taxable turnover in any rolling 12 months, every invoice to another business must be a VAT invoice. A full VAT invoice adds your VAT registration number, the VAT rate charged on each item, the unit price of each item, the total amount excluding VAT and the total VAT. Items at different rates (20%, 5% or 0%) are shown separately so the customer can reclaim the right amount. If you invoice in a foreign currency, the VAT must also be shown in pounds.

What does a compliant VAT invoice look like?

A VAT-registered training consultant supplies 10 hours of consultancy at £60 an hour, which is standard rated, and £120 of printed books, which are zero rated. The invoice must separate the rates.

Alongside the table the invoice shows the consultant’s VAT number, the supply date, the invoice date, both addresses and the invoice number. The invoice generator lays this out automatically and lets you set a different rate on each line; the VAT calculator is there if you need to check a single figure.

Construction has two extra rules. Subcontractors paid under the Construction Industry Scheme show the labour and materials split so the contractor can deduct CIS tax from the labour element, and VAT-registered subcontractors supplying other VAT-registered contractors must apply the domestic reverse charge: no VAT is added, and the invoice states that the customer must account for the VAT. If that is you, say so on every invoice.

What is not legally required but should be there?

• A due date. Without one, the law gives business customers 30 days.
• Bank details: account name, sort code and account number.
• Payment terms, and a note that statutory interest applies to late payment.
• The customer’s purchase order number if they gave you one.
• Your email and phone number, so a query reaches you quickly.

None of these affects whether the invoice is valid, but every one of them shortens the time it takes to get paid. See how to invoice as a sole trader for the full process.

What happens if an invoice is missing something?

For a non-VAT invoice, the practical risk is that the customer refuses to pay until it is corrected, and the legal risk is a dispute over whether a valid demand for payment was ever made. For a VAT invoice the stakes are higher: your customer cannot reclaim the VAT without a valid VAT invoice, and HMRC can penalise a registered business for issuing invoices that do not meet the rules. If you spot an error after sending, do not edit the original. Issue a credit note to cancel it and send a corrected invoice with the next number. Keep copies of all three.

How long do invoices need to be kept?

Sole traders keep invoices for at least five years after the 31 January filing deadline of the tax year they relate to. Limited companies keep them for six years from the end of the financial year. VAT-registered businesses keep VAT invoices for six years. Digital copies are fine, and if you are in Making Tax Digital for VAT the records must be digital anyway. A PDF of every invoice, named by number, in a folder you back up, satisfies all of this.